Guidelines for the use and interpretation of assays for monitoring autophagy

Cascade nanozymes based on glucose oxidase modified gold nanoclusters for enhanced synergistic cancer therapy via activated autophagy and apoptosis

Although cascade strategy based on starvation therapy and nanozymes synergistic therapy has shown its unique advantages in tumor treatment, the relatively large size of integrated nanoplatform and protective autophagy greatly reduces the therapeutic effects. Herein, we report an ultra-small cascade nanozyme for enhanced synergistic cancer therapy by using glucose oxidase (GOx) capped gold nanoclusters (AuNCs@GOx). The constructed AuNCs@GOx integrates starvation therapy, chemo-dynamic therapy (CDT) and autophagy modulation, which realizes efficient tumor treatment. GOx converts glucose into gluconic acid and H2O2, followed by the transformation from H2O2 to high-toxic ·OH via peroxidase mimic AuNCs. Notably, AuNCs@GOx activate autophagy via inhibiting the PI3K/AKT/mTOR signaling pathway and activating AMPK/mTOR/ULK1 signaling pathway in Hela cells, thereby synergizing with mitochondrial apoptosis to induce tumor cell death. In vitro experiments using multiple cancer cell lines (SKOV-3, MCF-7, HT-29, Hela and 4 T1) and normal cells (GES-1 and 293 T) demonstrates that AuNCs@GOx could specifically and significantly suppress the cancer cells growth without damaging the normal cells. Furthermore, AuNCs@GOx could effectively inhibit 4 T1 tumor growth with good biocompatibility in vivo. Overall, the introduction of AuNCs@GOx into tumor cells realizes effective cascade treatment of tumor, which induces enhanced CDT and starvation therapy through activating autophagy-mediated death pathway and inducing apoptosis.

Mito-Kaede photoactivation and chase experiment for mitophagy: mitophagy flux response toward various stimulations

Mitophagy, a crucial mitochondrial quality control system for cellular stress adaptation, is a key focus in pathophysiology and drug discovery. Developing a simple and versatile mitophagy flux assay is vital for advancing our understanding of cellular responses. Addressing a gap in systematic methods, we employ the photoactivatable fluorescent protein mito-Kaede in C2C12 myocytes, demonstrating its remarkable versatility in quantifying mitophagy flux responses under various stimuli, including carbonyl cyanide m-chlorophenyl hydrazone (CCCP), TNF-α, lipopolysaccharide (LPS), and hypoxia. This study underscores the validity and distinctive advantages of the mito-Kaede assay through comparative analysis with conventional assays including Western blotting (WB), potentially providing valuable insights for both mitophagy flux analysis and drug development.

Enterovirus 71 Induces Mitophagy via PINK1/Parkin Signaling Pathway to Promote Viral Replication

Enterovirus 71 (EV71) infection poses a global public health challenge, especially in infants and young children, with severe cases leading to fatal consequences. EV71 infection modulates various biological processes of the host and evades host immunity through multiple mechanisms. The balance of mitochondrial dynamics is important for cellular homeostasis. However, the mechanisms underlying EV71-induced cellular damage via mitophagy remain unclear. In the current study, we showed that EV71 infection significantly reduced the total and mitochondrial ATP contents in cells, as well as the expression of mitochondrial proteins TOM20 and TIM23. Then, EV71 infection increased the protein levels of PINK1, Parkin, and LC3B, suggesting that EV71 infection triggers the mitophagy. Silencing PINK1 caused a significant reduction in viral replication, while overexpressing Parkin promoted the replication of EV71. Moreover, CsA treatment, as a mitophagy inhibitor, alleviated pathological damage and suppressed the replication of EV71 in vivo. Mechanistic study showed that silencing PINK1 inhibited the cleavage of MAVS by EV71, while overexpressing Parkin enhanced the cleavage of MAVS by EV71, suggesting that PINK1-mediated mitophagy was involved in regulating innate immunity. Furthermore, we found that EV71 infection promoted the release of mitochondria carrying EV71 virions into the extracellular environment, which mediated infection of other cells, thus facilitating virus spreading. In addition, we also demonstrated that the extracellular mitochondria induced the degradation of MAVS and mitophagy promoted the release of mitochondria in EV71-infected HeLa cells. In conclusion, these findings suggest that EV71 infection induces PINK1-mediated mitophagy, which inhibits innate immunity and facilitates virus replication.

Ormeloxifene induces mitochondrial fission-mediated pro-death autophagy in colon cancer cells

Ormeloxifene (ORM) is a nonsteroidal selective estrogen receptor modulator (SERM), developed by the CSIR-Central Drug Research Institute that is approved as an oral contraceptive. However, it has also shown promising anti-cancer activity, especially in breast cancer. Here, we have investigated the anti-cancer effect of ORM on colon cancer cells and show that its antiproliferative activity is mediated through mitochondrial fission and autophagy-associated cell death. We observed that ORM treatment led to an elevation in autophagy markers like LC3II, Beclin1, and Atg7. Autophagy induction and LC3II turnover were monitored by immunofluorescence staining and confocal microscopy. Transmission electron microscopy results confirmed the formation of autophagosomes and autophagolysosomes. Autophagic flux was confirmed by the increased expression of LC3II in cells co-treated with BafilomycinA1(autophagy inhibitor) and ORM. This was further corroborated using tandem mRFP-GFP-LC3 (tfLC3) transfection in DLD-1 cells. Interestingly, we observed that inhibition of autophagy reduced the apoptotic cell population, suggesting pro-death autophagy. ORM treatment caused notable ultrastructural alterations indicative of cellular stress. Notably, ORM triggered the generation of mitochondrial ROS, associated with increased levels of mitochondrial fission and a decrease in mitochondrial fusion proteins. Changes in mitochondrial dynamics were observed under the TEM, which included reduced mitochondrial size and increased mitochondrial number. Inhibition of mitochondrial fission resulted in enhanced cell survival and a concomitant decrease in the autophagic markers, implying that ORM-induced autophagy depends on mitochondrial fission. Taken together, our findings bring to light a novel mechanism where Ormeloxifene targets mitochondrial dynamics to promote autophagy-associated cell death in colon cancer cells.

NLRP3 inflammasome inhibits mitophagy during the progression of temporal lobe epilepsy

Epilepsy is a neurological disorder involving mitochondrial dysfunction and neuroinflammation. This study examines the relationship between NLRP3 inflammasome activation and mitophagy in the temporal lobe epilepsy, which has not been reported before. A pilocarpine-induced epileptic rat model was used to assess seizure activity and neuronal loss. Pyroptosis markers (NLRP3, cleaved Gasdermin D, IL-1β/IL-18), and autophagy/mitophagy activity (LC3B-II/I, BNIP3, TOMM20/LC3B colocalization) were analyzed via immunofluorescence, Western blot, and transmission electron microscopy. NLRP3 inhibitors and anti-IL-1β antibodies were administered to evaluate therapeutic effects. Epileptic rats exhibited progressive neuronal loss and seizure aggravation, correlating with NLRP3 inflammasome activation and pyroptosis. While general autophagy was upregulated, mitophagy was selectively impaired in the hippocampus. NLRP3 activation promoted IL-1β release, which suppressed mitophagy via PPTC7 upregulation. NLRP3 activation inhibitor (MCC950) and anti-IL-1β treatment restored mitophagy and reduced seizures. NLRP3 inflammasome-driven pyroptosis exacerbates epilepsy by impairing mitophagy activity via IL-1β/PPTC7. Targeted NLRP3 inhibition mitigates this cascade, offering a promising strategy for refractory epilepsy.

Hepatic AKAP1 deficiency exacerbates diet-induced MASLD by enhancing GPAT1-mediated lysophosphatidic acid synthesis

Metabolic dysfunction-associated steatotic liver disease (MASLD), closely associated with obesity, can progress to metabolic dysfunction-associated steatohepatitis when the liver undergoes overt inflammatory damage. A-kinase anchoring protein 1 (AKAP1) has been shown to control lipid accumulation in brown adipocytes. However, the role of AKAP1 signaling in hepatic lipid metabolism and MASLD remains poorly understood. Here, we showed that hepatocyte-specific AKAP1 deficiency exacerbated hepatic steatosis and steatohepatitis in male mice subjected to a high-fat diet and fast-food diet, respectively. Mechanistically, AKAP1 directly phosphorylated and inactivated glycerol-3-phosphate acyltransferase 1 (GPAT1) in a PKA-dependent manner, thus suppressing lysophosphatidic acid (LPA) production. Increased endogenous LPA in hepatocytes promoted hepatocellular triglyceride (TG) synthesis and initiated pronounced inflammatory response in Kupffer cells. Restoring hepatic AKAP1 or repressing LPA levels via GPAT1 knockdown alleviated MASLD exacerbation. Overall, AKAP1 plays a protective role against MASLD by inhibiting GPAT1 activity, highlighting the potential of targeting AKAP1/PKA/GPAT1 signalosome for MASLD therapy.

Self-Assembly of Short Peptides Activates Specific ER-Phagy and Induces Pyroptosis for Enhanced Tumor Immunotherapy

Developing specific endoplasmic reticulum-autophagy (ER-phagy) inducers is highly desirable for discovering new ER-phagy receptors and elucidating the detailed ER-phagy mechanism and potential cancer immunotherapy. However, most of the current ER-phagy-inducing methods cause nonselective autophagy of other organelles. In this work, we report the design and synthesis of simple and stable short peptides (D-FFxFFs) that could specifically trigger ER-phagy, which further induces pyroptosis and activates the immune response against tumor cells. D-FFxFFs locate preferentially in ER and readily self-assemble to form nanosized misfolded protein mimics, which lead to distinct upregulation of dedicated ER-phagy receptors with no obvious autophagy of other organelles. Significant unfolded protein response (UPR) is activated via IRE1-JNK and PERK-ATF4 pathways. Interestingly, the persistent ER-phagy triggers ER Ca2+ release and a surge in mitochondrial Ca2+ levels, resulting in GSDMD-mediated pyroptosis other than apoptosis. The ER-phagy induces pyroptosis and activates a distinct antitumor immune response without evolving the acquired drug resistance. This work not only provides a powerful tool for investigating the mechanism and function of ER-phagy but also offers an appealing strategy for anticancer immunotherapy.

Aberrant aging-associated p62 autophagic cascade in biopsied olfactory neuronal cells from patients with psychosis

Sequestosome-1/p62, a key mediator in the clearance of damaged organelles and macromolecules during autophagy, serves as a marker of biological aging. We demonstrate elevated p62 in biopsied neuronal cells in patients with psychosis compared to healthy controls. In healthy controls, p62-indicated biological/autophagic age is positively correlated with chronological age over time, whereas in patients, neuronal p62-indicated biological/autophagic age shows no correlation with chronological age, being significantly higher than chronological age from the onset of the disease.

Hepatitis B surface antigen hijacks TANK-binding kinase 1 to suppress type I interferon and induce early autophagy

There are close links between innate immunity and autophagy. However, the crosstalk between innate immunity and autophagy in host cells infected with hepatitis B virus (HBV) remains unclear. Here, we reported that HBsAg suppressed type I interferon production and induced the accumulation of autophagosomes. HBsAg boosted TANK-binding kinase 1 (TBK1) phosphorylation and depressed interferon regulatory factor 3 (IRF3) phosphorylation ex vivo and in vivo. Mechanistic studies showed that HBsAg interaction with the kinase domain (KD) of TBK1 augmented its dimerization but disrupted TBK1-IRF3 complexes. Using the TBK1 inhibitor, BX795, we discovered that HBsAg-enhanced TBK1 dimerization, promoting sequestosome-1 (p62) phosphorylation, was necessary for HBV-induced autophagy and HBV replication. Moreover, HBsAg blocked autophagosome-lysosome fusion by inhibiting the synaptosomal-associated protein 29 (SNAP29) promoter. Notably, liver tissues from HBsAg transgenic mice or chronic HBV patients revealed that IFNβ signaling was inhibited and incomplete autophagy was induced. These findings suggest a novel mechanism by which HBsAg targets TBK1 to inhibit type I interferon and induce early autophagy, possibly leading to persistent HBV infection. Molecular mechanisms of HBsAg suppression of the IFNβ signaling pathway and triggering of early autophagy. HBsAg targets the kinase domain of TBK1, thereby disrupting the TBK1-IRF3 complex and inhibiting type I interferon production. On the other hand, HBsAg enhances TBK1 dimerization and phosphorylation, which upregulates the phosphorylation of p62 to induce p62-mediated autophagy. Furthermore, HBV infection causes the accumulation of autophagosomes. This is achieved by HBsAg suppressing the SNAP29 promoter activity, which blocks autophagosome-lysosome fusion.

R406 and its structural analogs reduce SNCA/α-synuclein levels via autophagic degradation

The presence of neuronal Lewy bodies mainly composed of SNCA/α-synuclein aggregations is a pathological feature of Parkinson disease (PD), whereas reducing SNCA protein levels may slow the progression of this disease. We hypothesized that compounds enhancing SNCA's interaction with MAP1LC3/LC3 May increase its macroautophagic/autophagic degradation. Here, we conducted small molecule microarray (SMM)-based screening to identify such compounds and revealed that the compound R406 could decrease SNCA protein levels in an autophagy-dependent manner. We further validated the proposed mechanism, in which knockdown of essential gene ATG5 for autophagy formation and using the autophagy inhibitor chloroquine (CQ) blocked the effect of R406. Additionally, R406 also reduced the levels of phosphorylated serine 129 of SNCA (p-S129-SNCA) in SNCA preformed fibrils (PFFs)-induced cellular models and rescued neuron degeneration. Importantly, we confirmed that R406 could alleviate PD-relevant disease phenotypes in human SNCA PFFs-induced cellular models and PD patient-derived organoid models. Taken together, we demonstrated the possibility of lowering SNCA levels by enhancing its autophagic degradation by compounds increasing SNCA-LC3 interactions.Abbreviations: ATTEC: autophagy-tethering compounds; BafA1: bafilomycin A1; BiFC: bimolecular fluorescence complementation; CQ: chloroquine; hMOs: human midbrain organoids; iPSC: induced pluripotent stem cells; MBP: maltose-binding protein; mHTT: mutant huntingtin; OI-RD: oblique-incidence reflectivity difference; PFFs: preformed fibrils; p-S129-SNCA: phosphorylated serine 129 of SNCA; PD: Parkinson disease; ROS: reactive oxygen species; siRNA: small interfering RNA; SMM: small molecule microarray; SNCA: synuclein alpha; SYK: spleen associated tyrosine kinase.

A non-fluorescent immunohistochemistry method for measuring autophagy flux using MAP1LC3/LC3 and SQSTM1 as core markers

Macroautophagy/autophagy is a crucial cellular process for degrading and recycling damaged proteins and organelles, playing a significant role in diseases such as cancer and neurodegeneration. Evaluating autophagy flux, which tracks autophagosome formation, maturation, and degradation, is essential for understanding disease mechanisms. Current fluorescence-based methods are resource-intensive, requiring advanced equipment and expertise, limiting their use in clinical laboratories. Here, we introduce a non-fluorescent immunohistochemistry (IHC) method using MAP1LC3/LC3 and SQSTM1 as core markers for autophagy flux assessment. LC3 levels reflect autophagosome formation, whereas SQSTM1 degradation and a decrease in the number of its puncta indicate active flux (i.e., lysosomal turnover). We optimized chromogenic detection using diaminobenzidine (DAB) staining and developed a scoring system based on puncta number and the percentage of stained cells. This accessible, cost-effective method enables reliable autophagy quantification using a standard light microscope, bridging the gap between experimental research and clinical diagnostics. Our protocol allows accurate autophagy evaluation in fixed tissues, offering practical applications in biomedical research and clinical pathology assessment.

TUT7-Mediated Uridine Degradation of MCPIP1 in the Pterygium to Regulate TRAF6-Mediated Autophagy

Purpose

Pterygium is a prevalent ocular disorder characterized by the proliferation of fibrovascular tissue beneath the conjunctiva. The precise role of monocyte chemotactic protein-induced protein 1 (MCPIP1) in the pterygium remains elusive.

Methods

Immunohistochemistry, Western blot, and quantitative RT-PCR were used to analyze the expression of MCPIP1 and other regulators. The role of MCPIP1 in pterygium fibrosis was assessed both in vitro and in vivo. Further, Co-immunoprecipitation and ubiquitination assays were performed to investigate the impact of MCPIP1 on the TRAF6-BECN1 signaling pathway. The role of MCPIP1 in autophagy regulation was studied through immunofluorescence experiments, while transwell migration and wound-healing assays were employed to assess the migratory and proliferative capabilities of human pterygium fibroblast (HPF) cells. Additionally, in vitro transcription and uridylylation experiments provided mechanistic insights into the regulatory role of terminal uridyltransferase 7 (TUT7) on MCPIP1 mRNA.

Results

The results showed that MCPIP1 negatively regulates the fibrosis and autophagy of HPF cells, thereby inhibiting the development of pterygium. In terms of its mechanism, MCPIP1 facilitated the assembly of the TRAF6-BECN1 complex, augmented BECN1 ubiquitination, induced autophagy, and attenuated cell migration and proliferation abilities while suppressing HPFs' cell fibrosis. The function of MCPIP1 was weakened by TUT7, which reduced the stability of MCPIP1 mRNA and thus alleviated the negative regulatory effect of MCPIP1 on pterygium.

Conclusions

In summary, the current study revealed that MCPIP1 promotes autophagy by positively regulating the TRAF6-BECN1 signaling pathway, thereby suppressing pterygium development. Conversely, TUT7 uridylylation modulated MCPIP1's regulation of pterygium.

Targeting of arachidonic acid-modulated autophagy to enhance the sensitivity of ROS1 + or ALK + non-small cell lung cancer to crizotinib therapy

Background

As an approved targeting drug, crizotinib has been widely used in the treatment of patients with non-small cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK) rearrangements or c-ros oncogene 1 (ROS1) fusions and has demonstrated remarkable therapeutic effects. However, crizotinib-treated patients frequently experience drug resistance, and there are still some underlying mechanisms, which remain unclear. Autophagy, a cellular process that involves the degradation and recycling of cellular components, has been implicated in the development of drug resistance. In this study, we aim to elucidate the mechanisms of crizotinib resistance involving autophagy dysregulation and identify novel therapeutic targets to overcome this resistance.

Methods

We first established a model for crizotinib resistance in HCC78 and H3122 cells. Next, the level of proliferation, apoptosis, autophagy flux, and reactive oxygen species (ROS) of these cells were measured. Subsequently, we analyzed the published single-cell RNA sequencing data from three ALK-rearranged lung cancer organoid samples and performed a metabolomics assay on crizotinib-resistant HCC78 cells. Finally, the therapeutic effects were confirmed in vitro by targeting autophagy flux.

Results

Crizotinib induced cell apoptosis and growth arrest by promoting the accumulation of autophagosomes through the inhibition of autophagy flux in ROS1 + or ALK + NSCLC. In contrast, crizotinib-resistant NSCLC cells showed inactivation of signal transducer and activator of transcription 3 (STAT3) phosphorylation and downregulation of prostaglandin endoperoxide synthase 2 (PTGS2), leading to an increase in the metabolite arachidonic acid (AA). AA further promoted autophagy flux and reduced autophagosome accumulation, driving crizotinib resistance under conditions of drug stress. Moreover, chloroquine (CQ), anti-malaria drug and lysosome inhibitor developed in 1940, could induce cell death in crizotinib-resistant NSCLC by blocking AA-mediated autophagy flux and facilitating autophagosome accumulation, significantly enhancing the treatment efficacy of crizotinib in drug-resistant NSCLC.

Conclusions

We discovered a new mechanism of first generation ALK- and ROS1-TKIs resistance, which points to the role of the metabolite AA in resistance to tyrosine kinase inhibitors. It may potentially provide an alternative strategy to overcoming crizotinib resistance in NSCLC treatment by reversing AA-mediated autophagy.

High-throughput screening identifies bazedoxifene as a potential therapeutic for dysferlin-deficient limb girdle muscular dystrophy

BACKGROUND AND PURPOSE

Limb-girdle muscular dystrophy R2 (LGMD R2) is a rare genetic disorder characterised by progressive weakness and wasting of proximal muscles. LGMD R2 is caused by the loss of function of dysferlin, a transmembrane protein crucial for plasma membrane repair in skeletal muscles. This study aimed to identify drugs that could improve the localisation and restore the function of an aggregated mutant form of dysferlin (DYSFL1341P).

EXPERIMENTAL APPROACH

We developed an in vitro high-throughput assay to monitor the expression and reallocation of aggregated mutant dysferlin (DYSFL1341P) in immortalised myoblasts. After screening 2239 clinically approved drugs and bioactive compounds, the ability of the more promising candidates to improve cell survival following hypo-osmotic shock was assessed. Their protective effects were evaluated on immortalised myoblasts carrying other dysferlin mutations and on dysferlin-deficient muscle fibres from Bla/J mice.

KEY RESULTS

We identified two compounds, saracatinib and bazedoxifene, that increase dysferlin content in cells carrying the DYSFL1341P mutation. Both drugs improved cell survival and plasma membrane resistance following osmotic shock. Whereas saracatinib acts specifically on misfolded L1341P dysferlin, bazedoxifene shows an additional protective effect on dysferlin KO immortalised myoblasts and mice muscle fibres. Further analysis revealed that bazedoxifene induces autophagy flux, which may enhance the survival of LGMD R2 myofibres.

CONCLUSION AND IMPLICATIONS

Our drug screening identified saracatinib and bazedoxifene as potential treatments for LGMD R2, especially for patients with the L1341P mutation. The widespread protective effect of bazedoxifene reveals a new avenue toward genotype-independent treatment of LGMD R2 patients.

What are the ethical limits of claimed scientific authorship? a case report of relevance

Since its discovery in the middle of the XX century, research into autophagy has undergone a spectacular expansion, particularly in the early 1990s. A number of physiological processes involving autophagy have been revealed and important human pathologies have been associated with perturbations in autophagy. In 2008 the "Guidelines for the use and interpretation of assays for monitoring autophagy" was launched with the purpose of collecting in a single document all the available information to monitor autophagy, which, it was thought, might be useful for established groups and any new scientists attracted by this field. The usefulness and success of this Guidelines has led to the subsequent publication of editions every 4 years, a task in which a growing number of authors have become involved and consequently included in the list of contributors. However, this worthy initiative and closely associated metric parameters has led to important scholarly repercussions in terms of perceived merits, grants and financial support obtained, professional careers and other areas concerning scientific activity. All these aspects are carefully examined in this contribution.

Methamphetamine and Methamphetamine-Induced Neuronal Exosomes Modulate the Activity of Rab7a via PTEN to Exert an Influence on the Disordered Autophagic Flux Induced in Neurons

Autophagy is a critical mechanism by which methamphetamine (METH) induces neuronal damage and neurotoxicity. Prolonged METH exposure can result in the accumulation of autophagosomes within cells. The autophagy process encompasses several essential vesicle-related biological steps, collectively referred to as the autophagic flux. However, the precise mechanisms by which METH modulates the autophagic flux and the underlying pathways remain to be elucidated. In this study, we utilized a chronic METH exposure mouse model and cell model to demonstrate that METH treatment leads to an increase in p62 and LC3B-II and the accumulation of autophagosomes in striatal neurons and SH-SY5Y cells. To assess autophagic flux, this study utilized autophagy inhibitors and inducers. The results demonstrated that the lysosomal inhibitor chloroquine exacerbated autophagosome accumulation; however, blocking autophagosome formation with 3-methyladenine did not prevent METH-induced autophagosome accumulation. Compared to the autophagy activator rapamycin, METH significantly reduced autophagosome-lysosome fusion, leading to autophagosome accumulation. Rab7a is a critical regulator of autophagosome-lysosome fusion. Although Rab7a expression was upregulated in SH-SY5Y cells and brain tissues after METH treatment, immunoprecipitation experiments revealed weakened interactions between Rab7a and the lysosomal protein RILP. Overexpression of active Rab7a (Rab7a Q67L) significantly alleviated the METH-induced upregulation of LC3-II and p62. PTEN, a key regulator of Rab7a dephosphorylation, was downregulated following METH treatment, resulting in decreased Rab7a dephosphorylation and reduced Rab7a activity, thereby contributing to autophagosome accumulation. We further investigated the role of neuronal exosomes in the autophagy process. Our results demonstrated that the miRNA expression profiles in exosomes released by METH-induced SH-SY5Y cells were significantly altered, with 122 miRNAs upregulated and 151 miRNAs downregulated. KEGG and GO enrichment analyses of these differentially expressed miRNAs and their target genes revealed significant associations with the autophagy pathway and potential regulation of PTEN expression. Our experiments confirmed that METH-induced exosomes reduced PTEN expression levels and decreased Rab7a dephosphorylation, thereby exacerbating autophagic flux impairment and autophagosome accumulation. In conclusion, our study indicated that METH and its induced neuronal exosomes downregulate PTEN expression, leading to reduced Rab7a dephosphorylation. This, in turn, hinders the fusion of autophagosomes and lysosomes, ultimately resulting in autophagic flux impairment and neuronal damage.

FAM43A coordinates mtDNA replication and mitochondrial biogenesis in response to mtDNA depletion

Mitochondrial retrograde signaling (MRS) pathways relay the functional status of mitochondria to elicit homeostatic or adaptive changes in nuclear gene expression. Budding yeast have "intergenomic signaling" pathways that sense the amount of mitochondrial DNA (mtDNA) independently of oxidative phosphorylation (OXPHOS), the primary function of genes encoded by mtDNA. However, MRS pathways that sense the amount of mtDNA in mammalian cells remain poorly understood. We found that mtDNA-depleted IMR90 cells can sustain OXPHOS for a significant amount of time, providing a robust model system to interrogate human intergenomic signaling. We identified FAM43A, a largely uncharacterized protein, as a CHK2-dependent early responder to mtDNA depletion. Depletion of FAM43A activates a mitochondrial biogenesis program, resulting in an increase in mitochondrial mass and mtDNA copy number via CHK2-mediated upregulation of the p53R2 form of ribonucleotide reductase. We propose that FAM43A performs a checkpoint-like function to limit mitochondrial biogenesis and turnover under conditions of mtDNA depletion or replication stress.

Restoring Autophagy by Exercise Ameliorates Insulin Resistance Partly via Calcineurin-Driven TFEB Nuclear Translocation

Exercise activates autophagy and lysosome system in skeletal muscle, which are known to play an important role in metabolic adaptation. However, the mechanism of exercise-activated autophagy and lysosome system in obese insulin resistance remains covert. In this study, we investigated the role of exercise-induced activation of autophagy and lysosome system in improving glucose metabolism of skeletal muscle. Male C57BL/6 mice were randomly divided into five groups: the chow diet (CD) group, the high-fat diet (HFD) group, the high-fat diet plus exercise (HFD-E) group and the HFD-E treated with calcineurin inhibitor FK506 (HFD-E-F) or saline (HFD-E-S) groups. The mice in exercise groups (HFD-E, HFD-E-F and HFD-E-S) were subjected to aerobic treadmill exercise (speed at 12 m/min for 1 h per session, 0° slope, 5 days per week for 12 weeks). Mice of HFD-E-F group were intraperitoneally administered FK506 (1 mg/kg), once each day for 2 weeks before the end of exercise. Expressions pTFEB, T-TFEB and autophagy-lysosome markers, including Beclin1, LC3, ULK1, SQSTM1, LAMP1, CTSD and CTSL proteins in gastrocnemius muscle were analysed. We demonstrated that HFD induced insulin resistance and decreased autophagy-lysosomal proteins and the exercise significantly increased transcription factor EB (TFEB) translocation from the cytoplasm to the nucleus, restored the impaired autophagy-lysosomal-related protein expressions, and improved glucose metabolism. The increase in TFEB nuclear translocation was partly blocked by the calcineurin inhibitor FK506. Our results suggest that exercise promotes autophagy and lysosome restoration by regulating calcineurin-mediated TFEB nuclear translocation, ultimately alleviating HFD-induced insulin resistance in mice skeletal muscle.

ATP6V1D drives hepatocellular carcinoma stemness and progression via both lysosome acidification-dependent and -independent mechanisms

Metabolic reprogramming is pivotal in cancer stem cell (CSC) self-renewal. However, the intricate regulatory mechanisms governing the crosstalk between metabolic reprogramming and liver CSCs remain elusive. Here, using a metabolic CRISPR-Cas9 knockout screen, we identify ATP6V1D, a subunit of the vacuolar-type H+-translocating ATPase (V-ATPase), as a key metabolic regulator of hepatocellular carcinoma (HCC) stemness. Elevated ATP6V1D expression correlates with poor clinical outcomes in HCC patients. ATP6V1D knockdown inhibits HCC stemness and malignant progression both in vitro and in vivo. Mechanistically, ATP6V1D enhances HCC stemness and progression by maintaining macroautophagic/autophagic flux. Specifically, ATP6V1D not only promotes lysosomal acidification, but also enhances the interaction between CHMP4B and IST1 to foster ESCRT-III complex assembly, thereby facilitating autophagosome-lysosome fusion to maintain autophagic flux. Moreover, silencing CHMP4B or IST1 attenuates HCC stemness and progression. Notably, low-dose bafilomycin A1 targeting the V-ATPase complex shows promise as a potential therapeutic strategy for HCC. In conclusion, our study highlights the critical role of ATP6V1D in driving HCC stemness and progression via the autophagy-lysosomal pathway, providing novel therapeutic targets and approaches for HCC treatment.Abbreviations: 3-MA: 3-methyladenine; ANT: adjacent normal liver tissues; ATP6V1D: ATPase H+ transporting V1 subunit D; BafA1: bafilomycin A1; CHMP: charged multivesicular body protein; co-IP: co-immunoprecipitation; CSC: cancer stem cell; ESCRT: endosomal sorting complex required for transport; HCC: hepatocellular carcinoma; IF: immunofluorescence; IHC: immunohistochemical; LCSCs: liver cancer stem cells; qRT-PCR: quantitative real time PCR; V-ATPase: vacuolar-type H+- translocating ATPase; WB: western blot.

GelMA@LNP/AST Promotes eNOS-Dependent Angiogenesis Through Autophagy Activation for the Treatment of Hind Limb Ischemia

Purpose

Limb ischemia is a refractory disease characterized by insufficient angiogenesis and tissue necrosis. Currently, the primary clinical treatment method is surgical intervention; however, the prognosis for patients with severe limb ischemia remains unsatisfactory. Although some studies have evaluated the effects of using bioactive factors to promote neovascularization and tissue repair, the clinical outcomes have not met expectations, possibly due to the difficulties in maintaining biological activity and avoiding potential side effects. Traditional Chinese medicine, specifically astilbin (AST), is a potential therapeutic agent in promoting tissue regeneration. However, there have been no reports on its efficacy in treating limb ischemia through promoting angiogenesis.

Materials and Methods

In this study, we prepared AST-loaded lignin nanoparticles (LNP/AST) with sustained-release functionality, which were mixed with GelMA hydrogel (GelMA@LNP/AST). The angiogenic effects were evaluated in a mouse model of hind limb ischemia. To further investigate the mechanism of angiogenesis, human endothelial cell line EA.hy926 was exposed to different concentrations of AST. The effects of AST on cell migration and angiogenesis were studied using wound healing assays and angiogenesis assays. The changes in angiogenesis markers, autophagy markers, and eNOS levels were detected using qPCR and Western blotting. 3-MA was used to assess the role of autophagy in the activation of eNOS mediated by AST and its subsequent angiogenic effects.

Results

GelMA@LNP/AST significantly promoted blood flow recovery in mice with hind limb ischemia. This effect was mainly attributed to the enhanced migration and angiogenic capabilities of endothelial cells mediated by AST. A potential underlying mechanism could be that the autophagy induced by AST increases eNOS activity.

Conclusion

GelMA@LNP/AST enables complete revascularization in female mice after hind limb ischemia, thereby achieving limb preservation and restoring motor function. Given the good therapeutic potential of the GelMA@LNP/AST in revascularization, it may become an effective strategy for successfully salvaging limbs in cases of limb ischemia.

Bombyx mori PAT4 gene inhibits BmNPV infection and replication through autophagy

Proton-assisted amino acid transporter 4 (PAT4) is a member of the solute carrier (SLC) 36 family, which mediates the transmembrane transport of amino acids and their derivatives. However, the function of PAT4 in Bombyx mori is not clear. In this study, BmPAT4 was cloned and identified using PCR technology. Its open reading frame (ORF) includes 1,395 bp, encoding 464 amino acid (Aa). Moreover, the sequence of BmPAT4 has the highest similarity with wild Bombyx.mandarina, Spodoptera frugiperda and Spodoptera litura, and it has ten transmembrane domains. BmPAT4 was localized in the cell membrane and expressed in all tissues of the silkworm. After Bombyx mori nuclear polyhedrosis virus (BmNPV) infection, the expression of BmPAT4 in midgut, hemolymph and fat body was significantly up-regulated. In addition, overexpression of BmPAT4 in BmN cells could significantly inhibit the proliferation of BmNPV, and the expression of several genes in autophagy pathway decreased significantly. On the contrary, down-regulation of BmPAT4 expression by RNA interference can promote BmNPV replication and proliferation, and the expression of key genes in autophagy pathway is significantly increased. This is the first time to report that BmPAT4 has an antiviral effect in silkworm. Moreover, the silkworm activates BmTORC1 via BmPAT4, which inhibits autophagy in silkworm cells, resulting in a lack of energy and raw materials for BmNPV infection and replication in cells.

Hotspots and frontiers of autophagy and chemotherapy in lung cancer: a bibliometric and visualization analysis from 2003 to 2023

Autophagy was considered to induce resistance in chemotherapy, which was significantly associated with proliferation of cancer; however, few bibliometric studies on the relation between autophagy and chemotherapy in lung cancer are available. The aim of the present study was to provide a comprehensive overview of the knowledge structure and research hotspots of autophagy and chemotherapy in lung cancer by bibliometric analysis. Publications related to autophagy and chemotherapy in lung cancer from 2003 to 2023 were searched on the Web of Science Core Collection (WoSCC) database. The bibliometric analysis was conducted by using VOSviewers, CiteSpace, and the R package "bibliometrix." A total of 675 articles from 70 countries, led by China and the United States, were included in the analysis. The number of publications related to autophagy and chemotherapy in lung cancer is increasing year by year. Nanjing Medical University, Zhejiang University, China Medical University, and Sichuan University are among the main research institutions contributing to this field. The journal Cancers is the most popular publication in this area, with Autophagy being the most co-cited journal. These publications involve 4481 authors, with Chiu Chien-chih and Gewirtz David having published the most papers, and Noboru Mizushima being the most frequently co-cited author. Studying the relation between autophagy and chemotherapy in the occurrence and development of lung cancer, and exploring therapeutic strategies involving autophagy and chemotherapy in lung cancer, are the primary topics in this research field. "Tumor stem cells," "microRNA," and "EGFR" emerge as the primary keywords in the emerging research hotspots. Indeed, this bibliometric study provides valuable insights into the research trends and developments concerning autophagy and chemotherapy in lung cancer. By identifying recent research frontiers and highlighting hot directions, this study serves as a valuable reference for scholars interested in understanding the relationship between autophagy and chemotherapy in lung cancer. The comprehensive summary of findings offers a foundation for further exploration and advancement in this critical area of cancer research.

Enhanced Parkin-mediated mitophagy mitigates adverse left ventricular remodelling after myocardial infarction: role of PR-364

BACKGROUND AND AIMS

Almost 30% of survivors of myocardial infarction (MI) develop heart failure (HF), in part due to damage caused by the accumulation of dysfunctional mitochondria. Organelle quality control through Parkin-mediated mitochondrial autophagy (mitophagy) is known to play a role in mediating protection against HF damage post-ischaemic injury and remodelling of the subsequent deteriorated myocardium.

METHODS

This study has shown that a single i.p. dose (2 h post-MI) of the selective small molecule Parkin activator PR-364 reduced mortality, preserved cardiac ejection fraction, and mitigated the progression of HF. To reveal the mechanism of PR-364, a multi-omic strategy was deployed in combination with classical functional assays using in vivo MI and in vitro cardiomyocyte models.

RESULTS

In vitro cell data indicated that Parkin activation by PR-364 increased mitophagy and mitochondrial biogenesis, enhanced adenosine triphosphate production via improved citric acid cycle, altered accumulation of calcium localization to the mitochondria, and initiated translational reprogramming with increased expression of mitochondrial translational proteins. In mice, PR-364 administered post-MI resulted in widespread proteome changes, indicating an up-regulation of mitochondrial metabolism and mitochondrial translation in the surviving myocardium.

CONCLUSIONS

This study demonstrates the therapeutic potential of targeting Parkin-mediated mitophagy using PR-364 to protect surviving cardiac tissue post-MI from progression to HF.

Defective Mitophagy Impairs Response to Inflammatory Activation of Macrophage-Like Cells

BACKGROUND AND AIMS

The role of mitophagy in atherosclerosis has been extensively studied during the last few years. It was shown that mitophagy is involved in the regulation of macrophages, which are important players as immune cells in atherosclerosis development. In this study, we investigated the relationship between mitophagy and response to inflammatory stimulation of macrophage-like cells. Six cybrid cell lines with normal mitophagy, that is, increasing in response to stimulation, and 7 lines with defective mitophagy not responding to stimulation were obtained. The objective of the study was to compare the nature of the inflammatory response in normal and defective mitophagy in order to elucidate the role of mitophagy defects in inflammation.

METHODS

We used cytoplasmic hybrids (cybrids) as cellular models, created using mitochondrial DNA from different atherosclerosis patients. Mitophagy was stimulated by carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and assessed as the degree of colocalization of mitochondria with lysosomes using confocal microscopy. Western blotting methods were used for the determination of proteins involved in the exact mechanism of mitophagy. Experiments with stimulation of mitophagy show a high correlation between these two approaches (microscopy and blotting). The pro-inflammatory response of cybrids was stimulated with bacterial lipopolysaccharide (LPS). The extent of the inflammatory response was assessed by the secretion of cytokines CCL2, IL8, IL6, IL1β, and TNF measured by ELISA.

RESULTS

Basal level of secretion of cytokines CCL2, IL8 and TNF was 1.5-2 times higher in cultures of cybrids with defective mitophagy compared to cells with normal mitophagy. This suggests a persistently elevated inflammatory response in cells with defective mitophagy, even in the absence of an inflammatory stimulus. Such cells in the tissue will constantly recruit other immune cells, which is characteristic of macrophages derived from monocytes circulating in the blood of patients with atherosclerosis. We observed significant differences in the degree and type of response to inflammatory activation in cybrids with defective mitophagy. These differences were not so much quantitative as they were dramatically qualitative. Compared with cells with normal mitophagy, in cells with defective mitophagy, the relative (to basal) secretion of IL8, IL6 and IL1b increased after the second LPS activation. This indicates a possible lack of tolerance to inflammatory activation in cells with defective mitophagy, since typically, re-activation reveals a smaller pro-inflammatory cytokine response, allowing the inflammatory process to resolve. In cells with normal mitophagy, exactly this normal (tolerant) inflammatory reaction was observed.

CONCLUSION

Data on the involvement of mitophagy, including defective mitophagy, in disturbances of the inflammatory response in sepsis, viral infections, autoimmune diseases and other pathologies have previously been reported. In this work, we studied the role of defective mitophagy in non-infectious chronic inflammatory diseases using the example of atherosclerosis. We showed a dramatic disruption of the inflammatory response associated with defective mitophagy. Compared with cybrids with normal mitophagy, in cybrids with defective mitophagy, the secretion of all studied cytokines changed significantly both quantitatively and qualitatively. In particular, the secretion of 3 of 5 cytokines demonstrated an intolerant inflammatory response manifested by increased secretion after repeated inflammatory stimulation. Such an intolerant reaction likely indicates a significant disruption of the pro-inflammatory response of macrophages, which can contribute to the chronification of inflammation. Elucidating the mechanisms of chronification of inflammation is extremely important for the search for fundamentally new pharmacological targets and the development of drugs for the prevention and treatment of chronic inflammatory diseases, including atherosclerosis and diseases characteristic of inflammation. Such diseases account for up to 80% of morbidity and mortality.

ErbB2-NOTCH1 axis controls autophagy in cardiac cells

Although the epidermal growth factor receptor 2 (ErbB2) and Notch1 signaling pathways have both significant roles in regulating cardiac biology, their interplay in the heart remains poorly investigated. Here, we present evidence of a crosstalk between ErbB2 and Notch1 in cardiac cells, with effects on autophagy and proliferation. Overexpression of ErbB2 in H9c2 cardiomyoblasts induced Notch1 activation in a post-transcriptional, p38-dependent manner, while ErbB2 inhibition with the specific inhibitor, lapatinib, reduced Notch1 activation. Moreover, incubation of H9c2 cells with lapatinib resulted in stalled autophagic flux and decreased proliferation, consistent with the established cardiotoxicity of this and other ErbB2-targeting drugs. Confirming the findings in H9c2 cells, exposure of primary neonatal mouse cardiomyocytes to exogenous neuregulin-1, which engages ErbB2, stimulated proliferation, and this effect was abrogated by concomitant inhibition of the enzyme responsible for Notch1 activation. Furthermore, the hearts of transgenic mice specifically overexpressing ErbB2 in cardiomyocytes had increased levels of active Notch1 and of Notch-related genes. These data expand the knowledge of ErbB2 and Notch1 functions in the heart and may allow better understanding the mechanisms of the cardiotoxicity of ErbB2-targeting cancer treatments.

A Decrease in Autophagy Increases the Level of Collagen Type I Expression in Scleral Fibroblasts

PURPOSE

Autophagy dysregulation triggers extracellular matrix remodeling via changes in cellular collagen levels and protease secretion. However, the effect of autophagy on scleral extracellular matrix remodeling in the context of myopia is not fully understood. In this study, we measured the level of autophagy in sclera of form deprivation myopic guinea pigs; we also sought a correlation between the level of autophagy in human scleral fibroblasts and the extent of COL1A1 synthesis.

METHODS

We measured the level of COL1A1 expression and the levels of autophagic protein markers in scleral tissues in vivo using a form deprivation myopic guinea pig model. Rapamycin and chloroquine were respectively used to activate and inhibit autophagy in cultured human scleral fibroblasts. COL1A1 gene and protein expression levels were analyzed via quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence. Levels of autophagy-related proteins were assessed via Western blotting.

RESULTS

The sclera of form deprivation myopic guinea pig eyes exhibited decreased expression of COL1A1 and increased expression level of autophagy. After chloroquine exposure, human scleral fibroblasts exhibited decreased autophagy and increased COL1A1 expression.

CONCLUSION

Inhibition of scleral fibroblast autophagy increased COL1A1 expression at the gene and protein levels, thus explaining the effect of autophagy on collagen synthesis by scleral fibroblasts.

Astrocytes initiate autophagic flux and maintain cell viability after internalizing non-active native extracellular α-synuclein

Astrocytes are tasked with regulating the synaptic environment. Early stages of various neurodegenerative diseases are characterized by synapse loss, and astrocytic atrophy and dysfunction has been proposed as a possible cause. α-Synuclein (αS) is a highly expressed neuronal protein located in the synapse that can be released in the extracellular space. Evidence points to astrocytes as being responsible for uptake and degradation of extracellular αS. Therefore, misfolded active fibrillized αS resulting in protein inclusions and aggregates could be due to astrocytic dysfunction. Despite these pathological hallmarks and lines of evidence, the autophagic function of astrocytes in response to monomeric non-active αS to model healthy conditions has not been investigated. Human primary cortical astrocytes were treated with 100 nM of extracellular monomeric non-active αS alone, and in combination with N-terminal binding monomeric γ-synuclein (γS) as a control. Western blot analysis and super resolution imaging of HiLyte-488 labeled αS confirmed successful internalization of αS at 12, 24 and 48 h after treatment, while αS dimers were only observed at 48 h. Western blot analysis also confirmed αS's ability to induce autophagic flux by 48 h. Annexin V/PI flow cytometry results revealed increased early apoptosis at 24 h, but which resolved itself by 48 h, indicating no cell death in cortical astrocytes at all time points, suggesting astrocytes can manage the protein degradation demand of monomeric αS in healthy physiological conditions. Likewise, astrocytes reduced secretion of apolipoprotein (ApoE), a protein involved in pro-inflammatory pathways, synapse regulation, and autophagy by 12 h. Similarly, total c-JUN protein levels, a transcription factor involved in pro-inflammatory pathways increased by 12 h in the nuclear fraction. Therefore, astrocytes are able to respond and degrade αS in healthy physiological conditions, and astrocyte dysfunction could precede detrimental αS accumulation.

Beclin-1 and LC3B expression in canine mast cell tumours: an immuno-ultrastructural and immunohistochemical study of autophagy

Mast cell tumours (MCTs) are common malignant neoplasms in dogs, for which prognosis and therapeutic decisions are based on histological features and proliferation markers. Autophagy is a cellular catabolic process responsible for degrading cytoplasmic components to maintain homeostasis, alterations in which are frequently linked to tumour growth and progression. This study was conducted to investigate the occurrence of autophagy in canine MCTs and to verify its value as a prognostic indicator for dogs with the disease. Beclin-1 and LC3B expressions were investigated using immunohistochemistry, and autophagy was ultrastructurally characterised. The autophagic phenomenon was successfully visualised in neoplastic mast cells under transmission electron and immunoelectron microscopy. MCTs from dogs that died due to the disease showed higher positivity for Beclin-1 and dogs with MCTs presenting a LC3B granular immunohistochemical pattern had a significantly shorter post-surgical survival. The occurrence of autophagy is an indicator of poor prognosis. Future studies are needed to elucidate the specific mechanisms and open new opportunities to treatments targeting this cancer cell advantage.

The role of HDAC6 in enhancing macrophage autophagy via the autophagolysosomal pathway to alleviate legionella pneumophila-induced pneumonia

Legionella pneumophila (L. pneumophila) is a prevalent pathogenic bacterium responsible for significant global health concerns. Nonetheless, the precise pathogenic mechanisms of L. pneumophila have still remained elusive. Autophagy, a direct cellular response to L. pneumophila infection and other pathogens, involves the recognition and degradation of these invaders in lysosomes. Histone deacetylase 6 (HDAC6), a distinctive member of the histone deacetylase family, plays a multifaceted role in autophagy regulation. This study aimed to investigate the role of HDAC6 in macrophage autophagy via the autophagolysosomal pathway, leading to alleviate L. pneumophila-induced pneumonia. The results revealed a substantial upregulation of HDAC6 expression level in murine lung tissues infected by L. pneumophila. Notably, mice lacking HDAC6 exhibited a protective response against L. pneumophila-induced pulmonary tissue inflammation, which was characterized by the reduced bacterial load and diminished release of pro-inflammatory cytokines. Transcriptomic analysis has shed light on the regulatory role of HDAC6 in L. pneumophila infection in mice, particularly through the autophagy pathway of macrophages. Validation using L. pneumophila-induced macrophages from mice with HDAC6 gene knockout demonstrated a decrease in cellular bacterial load, activation of the autophagolysosomal pathway, and enhancement of cellular autophagic flux. In summary, the findings indicated that HDAC6 knockout could lead to the upregulation of p-ULK1 expression level, promoting the autophagy-lysosomal pathway, increasing autophagic flux, and ultimately strengthening the bactericidal capacity of macrophages. This contributes to the alleviation of L. pneumophila-induced pneumonia.

The COPII coat protein SEC24D is required for autophagosome closure in mammals

Macroautophagy involves the encapsulation of cellular components within double-membrane autophagosomes for subsequent degradation in vacuoles or lysosomes. Coat protein complex II (COPII) vesicles serve as a membrane source for autophagosome formation. However, the specific role of SEC24D, an isoform of the COPII coat protein SEC24, in the macroautophagy pathway remains unclear. In this study, we demonstrate that SEC24D is indispensable for macroautophagy and important for autophagosome closure. Depletion of SEC24D leads to the accumulation of unsealed isolation membranes. Furthermore, under conditions of starvation, SEC24D interacts with casein kinase1 delta (CK1δ), a member of the casein kinase 1 family, and autophagy-related 9A (ATG9A). Collectively, our findings unveil the indispensable role of SEC24D in starvation-induced autophagy in mammalian cells.

The role of autophagy dysregulation in low and high-grade nonmuscle invasive bladder cancer: A survival analysis and clinicopathological association

INTRODUCTION

Bladder cancer disproportionately affects men and often presents as nonmuscle-invasive bladder cancer (NMIBC). Despite initial treatments, the recurrence and progression of NMIBC are linked to autophagy. This study investigates the expression of autophagy genes (mTOR, ULK1, Beclin1, and LC3) in low and high-grade NMIBC, providing insights into potential prognostic markers and therapeutic targets.

MATERIAL AND METHODS

A total of 115 tissue samples (n = 85 NMIBC (pTa, pT1, and CIS) and n = 30 control from BPH patients) were collected. The expression level of autophagy genes (mTOR, ULK1, Beclin1, and LC3) and their proteins were assessed in low and high-grade NMIBC, along with control tissue samples using quantitative real-time polymerase chain reaction and western blotting. Association with clinicopathological characteristics and autophagy gene expression was analyzed by multivariate and univariate survival analysis using SPSS.

RESULT

In high-grade NMIBC, ULK1, P = 0.0150, Beclin1, P = 0.0041, and LC3, P = 0.0014, were substantially downregulated, whereas mTOR, P = 0.0006, was significantly upregulated. The KM plots show significant survival outcomes with autophagy genes. The clinicopathological characters, high grade (P = 0.019), tumor stage (CIS P = 0.039, pT1 P = 0.018, P = 0.045), male (P = 0.010), lymphovascular invasion (P = 0.028) and autophagy genes (ULK1 P = 0.002, beclin1 (P = 0.010, P = 0.022) were associated as risk factors for survival outcome in NMIBC patients.

CONCLUSION

The upregulated mTOR, downregulated ULK1, and beclin1 expression is linked to a high-grade, CIS and pT1 stage, resulting in poor recurrence-free survival and progression-free survival and highlights the prognostic significance of autophagy gene in nonmuscle-invasive bladder cancer.

Increased Rab1a accelerates osteoarthritis by inhibiting autophagy via activation of the mTORC1-S6K pathway

INTRODUCTION

Cartilage degradation is a critical alteration in the progression of osteoarthritis (OA) due to the disorder of chondrocyte metabolic homeostasis. Autophagy plays an important role in maintaining intracellular homeostasis. Recent investigations have increasingly underscored the importance of autophagy in modulating the pathological mechanisms underlying OA. Ras-related protein Rab-1a (Rab1a) has been illustrated to regulate autophagy in many diseases but not in OA.

OBJECTIVES

This study aims to elucidate whether Rab1a could regulate the development of OA through modulation of chondrocyte autophagy and apoptosis.

METHODS

Proteomic sequencing, Western blotting, and immunohistochemistry were applied to detect the expression level of Rab1a in vitro and in vivo. Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways were rigorously identified. The effects of Rab1a and the interaction between Rab1a, mTORC1, autophagy and apoptosis were explored by qPCR, Western blotting, and immunofluorescence. An experimental mouse OA model was also performed to confirm the role of Rab1a in OA pathogenesis in vivo. Histological analysis was employed to demonstrate cartilage damage.

RESULTS

Rab1a expression was significantly upregulated in inflamed chondrocytes and knee OA cartilage. Inhibition of Rab1a partially attenuated the degradation of the extracellular matrix and cell apoptosis both in vitro and in vivo, whereas overexpression of Rab1a intensified cartilage matrix degradation and cellular apoptosis. Additionally, elevated Rab1a levels were observed to suppress autophagy and activate the mTORC1-S6K signaling pathway, thereby aggravating OA pathogenesis.

CONCLUSION

The augmentation of Rab1a expression impairs autophagy and promotes apoptosis through the activation of the mTORC1-S6K signaling pathway, further exacerbating OA pathogenesis. This finding suggests that Rab1a serves as a promising and innovative therapeutic target for the prevention and treatment of OA.

miR-93-5p impairs autophagy-lysosomal pathway via TET3 after subarachnoid hemorrhage

Intact autophagy-lysosomal pathway (ALP) in neuronal survival is crucial. However, it remains unclear whether ALP is intact after subarachnoid hemorrhage (SAH). Ten-eleven translocation (TET) 3 primarily regulates genes related to autophagy in neurons in neurodegenerative diseases. This study aims to investigate the role of TET3 in the ALP following SAH. The results indicate that the ALP is impaired after SAH, with suppressed autophagic flux and an increase in autophagosomes. This is accompanied by a decrease in TET3 expression. Activation of TET3 by α-KG can improve ALP function and neural function to some extent. Silencing TET3 in neurons significantly inhibited the ALP function and increased apoptosis. Inhibition of miR-93-5p, which is elevated after SAH, promotes TET3 expression. This suggests that the downregulation of TET3 after SAH is, at least in part, due to elevated miR-93-5p. This study clarifies the key role of TET3 in the functional impairment of the ALP after SAH. The preliminary exploration revealed that miR-93-5p could lead to the downregulation of TET3, which could be a new target for neuroprotective therapy after SAH.

ARRB1 inhibits extracellular matrix degradation and apoptosis of nucleus pulposus cells by promoting autophagy and attenuates intervertebral disc degeneration

OBJECTIVE

Intervertebral disc degeneration (IVDD) is the leading cause of lower back pain (LBP). β-arrestin 1 (ARRB1) is a multifunctional protein that regulates numerous pathological processes. The aim of this study was to investigate the role of ARRB1 in IVDD.

METHODS

The expression of ARRB1 in nucleus pulposus (NP) of rats with IVDD was assayed. Next, rat nucleus pulposus cells (NPCs) were infected with lentiviruses containing shArrb1 (LV-shArrb1) and overexpressing Arrb1 (LV-oeArrb1). The roles of Arrb1 in serum-deprived NPCs were investigated by measuring apoptosis, extracellular matrix degradation, and autophagic flux. For experiments in vivo, LV-oeArrb1 lentivirus was injected into the NP tissues of IVDD rats to evaluate the effects of Arrb1 overexpression on NP.

RESULTS

In the NP tissues of IVDD rats, ARRB1 and cleaved caspase-3 expression increased, and the ratio of LC3II/LC3I protein expression was upregulated. Arrb1 knockdown aggravated extracellular matrix degradation, cellular apoptosis, and impairment of autophagic flux in rat NPCs under serum-deprived conditions, whereas Arrb1 overexpression significantly reversed these effects. ARRB1 interacted with Beclin 1, and Arrb1 knockdown suppressed the formation of the Beclin1-PIK3C3 core complex. The autophagy inhibitor 3-methyladenine (3-MA) offset the protective effects of Arrb1 overexpression in serum-deprived NPCs. Furthermore, Arrb1 overexpression inhibited apoptosis and extracellular matrix degradation, promoted autophagy in NP, and delayed the development of IVDD in rats.

CONCLUSION

ARRB1 prevents extracellular matrix degradation and apoptosis of NPCs by upregulating autophagy and ameliorating IVDD progression, presenting an innovative strategy for the treatment of IVDD.

Exotoxins secreted by Clostridium septicum induce macrophage death: Implications for bacterial immune evasion mechanisms at infection sites

The induction of macrophage death is considered a potential mechanism by which components secreted by Clostridium septicum are used to evade the innate immune response and cause tissue damage. This study aimed to determine the effects of partially purified fractions of extracellular proteins secreted by C. septicum on the death of mouse peritoneal macrophages. Elicited mouse peritoneal macrophages were incubated with partially purified fractions of proteins secreted by C. septicum into the culture medium. After incubation, the protein fraction with a molecular weight ≥100 kDa caused significant cell death in macrophages, altered cell morphology, increased the expression of markers of apoptosis and autophagy, and increased the expression (protein and mRNA) of IL-10 and TNFα. Our data suggest that the proteins secreted by C. septicum (MW, ≥100 kDa) induce cell death in macrophages by promoting autophagy-triggered apoptosis. This study may contribute to our understanding of the molecular mechanism of immune evasion by C. septicum at the infection site.

Uropathogenic Escherichia coli Subverts Host Autophagic Defenses by Stalling Preautophagosomal Structures to Escape Lysosome Exocytosis

Urinary tract infections are primarily caused by uropathogenic Escherichia coli (UPEC). UPEC infects bladder epithelial cells (BECs) via fusiform vesicles and escapes into the cytosol by disrupting fusiform vesicle membrane using outer membrane phospholipase PldA, and establishes biofilm-like intracellular bacterial communities (IBCs) for protection from host immune clearance. Cytosolic UPEC is captured by autophagy to form autophagosomes, then transported to lysosomes, triggering the spontaneous exocytosis of lysosomes. The mechanism by which UPEC evades autophagy to recognize and form IBCs remains unclear. Here, we demonstrate that by inhibiting autophagic flux, UPEC PldA reduces the lysosome exocytosis of BECs. By reducing intracellular phosphatidylinositol 3-phosphate levels, UPEC PldA increases the accumulation of NDP52 granules and decreases the targeting of NDP52 to autophagy, hence stalling preautophagosome structures. Thus, our results uncover a critical role for PldA to inhibit autophagic flux, favoring UPEC escapes from lysosome exocytosis, thereby contributing to acute urinary tract infection.

Targeting IGF1/IGF1r signaling relieve pain and autophagic dysfunction in NTG-induced chronic migraine model of mice

BACKGROUND

Chronic migraine is a severe and common neurological disorder, yet its precise physiological mechanisms remain unclear. The IGF1/IGF1r signaling pathway plays a crucial role in pain modulation. Studies have shown that IGF1, by binding to its receptor IGF1r, activates a series of downstream signaling cascades involved in neuronal survival, proliferation, autophagy and functional regulation. The activation of these pathways can influence nociceptive transmission. Furthermore, alterations in IGF1/IGF1r signaling are closely associated with the development of various chronic pain conditions. Therefore, understanding the specific mechanisms by which this pathway contributes to pain is of significant importance for the development of novel pain treatment strategies. In this study, we investigated the role of IGF1/IGF1r and its potential mechanisms in a mouse model of chronic migraine.

METHODS

Chronic migraine was induced in mice by repeated intraperitoneal injections of nitroglycerin. Mechanical and thermal hypersensitivity responses were assessed using Von Frey filaments and radiant heat, respectively. To determine the role of IGF1/IGF1r in chronic migraine (CM), we examined the effects of the IGF1 receptor antagonist ppp (Picropodophyllin) on pain behaviors and the expression of calcitonin gene-related peptide (CGRP) and c-Fos.

RESULT

In the nitroglycerin-induced chronic migraine model in mice, neuronal secretion of IGF1 is elevated within the trigeminal nucleus caudalis (TNC). Increased phosphorylation of the IGF1 receptor occurs, predominantly co-localizing with neurons. Treatment with ppp alleviated basal mechanical hypersensitivity and acute mechanical allodynia. Furthermore, ppp ameliorated autophagic dysfunction and reduced the expression of CGRP and c-Fos.

CONCLUSION

Our findings demonstrate that in the chronic migraine (CM) model in mice, there is a significant increase in IGF1 expression in the TNC region. This upregulation of IGF1 leads to enhanced phosphorylation of IGF1 receptors on neurons. Targeting and inhibiting this signaling pathway may offer potential preventive strategies for mitigating the progression of chronic migraine.

ESCRT disruption provides evidence against trans-synaptic signaling via extracellular vesicles

Extracellular vesicles (EVs) are released by many cell types, including neurons, carrying cargoes involved in signaling and disease. It is unclear whether EVs promote intercellular signaling or serve primarily to dispose of unwanted materials. We show that loss of multivesicular endosome-generating endosomal sorting complex required for transport (ESCRT) machinery disrupts release of EV cargoes from Drosophila motor neurons. Surprisingly, ESCRT depletion does not affect the signaling activities of the EV cargo Synaptotagmin-4 (Syt4) and disrupts only some signaling activities of the EV cargo evenness interrupted (Evi). Thus, these cargoes may not require intercellular transfer via EVs, and instead may be conventionally secreted or function cell-autonomously in the neuron. We find that EVs are phagocytosed by glia and muscles, and that ESCRT disruption causes compensatory autophagy in presynaptic neurons, suggesting that EVs are one of several redundant mechanisms to remove cargoes from synapses. Our results suggest that synaptic EV release serves primarily as a proteostatic mechanism for certain cargoes.

SCFFBXW5-mediated degradation of AQP3 suppresses autophagic cell death through the PDPK1-AKT-MTOR axis in hepatocellular carcinoma cells

AQP3 (aquaporin 3 (Gill blood group)), a member of the AQP family, is an aquaglyceroporin which transports water, glycerol and small solutes across the plasma membrane. Beyond its role in fluid transport, AQP3 plays a significant role in regulating various aspects of tumor cell behavior, including cell proliferation, migration, and invasion. Nevertheless, the underlying regulatory mechanism of AQP3 in tumors remains unclear. Here, for the first time, we report that AQP3 is a direct target for ubiquitination by the SCFFBXW5 complex. In addition, we revealed that downregulation of FBXW5 significantly induced AQP3 expression to prompt macroautophagic/autophagic cell death in hepatocellular carcinoma (HCC) cells. Mechanistically, AQP3 accumulation induced by FBXW5 knockdown led to the degradation of PDPK1/PDK1 in a lysosomal-dependent manner, thus inactivating the AKT-MTOR pathway and inducing autophagic death in HCC. Taken together, our findings revealed a previously undiscovered regulatory mechanism through which FBXW5 degraded AQP3 to suppress autophagic cell death via the PDPK1-AKT-MTOR axis in HCC cells.Abbreviation: BafA1: bafilomycin A1; CQ: chloroquine; CRL: CUL-Ring E3 ubiquitin ligases; FBXW5: F-box and WD repeat domain containing 5; HCC: hepatocellular carcinoma; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; 3-MA: 3-methyladenine; PDPK1/PDK1: 3-phosphoinositide dependent protein kinase 1; RBX1/ROC1: ring-box 1; SKP1: S-phase kinase associated protein 1; SCF: SKP1-CUL1-F-box protein.

Progranulin Protects against Aspergillus fumigatus Keratitis by Attenuating the Inflammatory Response through Enhancing Autophagy

Fungal keratitis (FK) is a severe corneal condition caused by pathogenic fungi and is associated with the virulence of fungi and an excessive tissue inflammatory response. Progranulin (PGRN), functioning as a multifunctional growth factor, exerts a pivotal influence on the regulation of inflammation and autophagy. The aim of our research was to analyze the role of PGRN in Aspergillus fumigatus (A. fumigatus) keratitis. We found that PGRN expression was increased in the mouse cornea with A. fumigatus keratitis. In our experiments, corneas of mice with FK were treated with 100 ng/mL of PGRN. In vitro, RAW 264.7 cells were treated with 10 ng/mL of PGRN before A. fumigatus stimulation. The findings suggested that PGRN effectively alleviated corneal edema and decreased the expression of pro-inflammatory cytokines in mice. In stimulated RAW 264.7 cells, PGRN treatment suppressed the expression of pro-inflammatory cytokines IL-6 and TNF-α but promoted the expression of the anti-inflammatory cytokines IL-10. PGRN treatment significantly upregulated the expression of autophagy-related proteins LC3, Beclin-1, and Atg-7. 3-Methyladenine (3-MA, autophagy inhibitor) reversed the regulation of inflammatory cytokines by PGRN. In addition, our study demonstrated that PGRN also enhanced phagocytosis in RAW 264.7 cells. In summary, PGRN attenuated the inflammatory response of A. fumigatus keratitis by increasing autophagy and enhanced the phagocytic activity of RAW 264.7 cells. This showed that PGRN had a protective effect on A. fumigatus keratitis.

AMPK regulates phagophore-to-autophagosome maturation

Autophagy is an important metabolic pathway that can non-selectively recycle cellular material or lead to targeted degradation of protein aggregates or damaged organelles. Autophagosome formation starts with autophagy factors accumulating on lipid vesicles containing ATG9. These phagophores attach to donor membranes, expand via ATG2-mediated lipid transfer, capture cargo, and mature into autophagosomes, ultimately fusing with lysosomes for their degradation. Autophagy can be activated by nutrient stress, for example, by a reduction in the cellular levels of amino acids. In contrast, how autophagy is regulated by low cellular ATP levels via the AMP-activated protein kinase (AMPK), an important therapeutic target, is less clear. Using live-cell imaging and an automated image analysis pipeline, we systematically dissect how nutrient starvation regulates autophagosome biogenesis. We demonstrate that glucose starvation downregulates autophagosome maturation by AMPK-mediated inhibition of phagophore tethering to donor membrane. Our results clarify AMPKs regulatory role in autophagy and highlight its potential as a therapeutic target to reduce autophagy.

The matrix protein of lyssavirus hijacks autophagosome for efficient egress by recruiting NEDD4 through its PPxY motif

Lyssaviruses are well-known worldwide and often cause fatal encephalitis. Previous studies have shown that autophagy is beneficial for the replication of rabies virus (RABV), the representative lyssavirus, but the detailed mechanism remains obscure. In this study, we showed that the rabies virus matrix protein (RABV-M) used its PPxY motif to interact with the E3 ubiquitin-protein ligase NEDD4. NEDD4 then recruited MAP1LC3/LC3 via its LC3-interacting region (LIR). Interestingly, after binding to the ubiquitinated RABV-M, NEDD4 could bind more LC3 and enhance autophagosome accumulation, while NEDD4 knockdown significantly reduced M-induced autophagosome accumulation. Further study revealed that RABV-M prevented autophagosome-lysosome fusion and facilitated viral budding. Inhibition of RABV-M-induced autophagosome accumulation reduced the production of extracellular virus-like particles. We also found that M proteins of most lyssaviruses share the same mechanism to accumulate autophagosome by hijacking NEDD4. Collectively, this study revealed a novel strategy for lyssaviruses to achieve efficient viral replication by exploiting the host autophagy system.Abbreviations: ABLV: Australian bat lyssavirus; ATG5: autophagy related 5; Baf A1:bafilomycin A1;co-IP: co-immunoprecipitation; CQ: chloroquine; DAPI:4',6-diamidino-2'-phenylindole; DMSO: dimethyl sulfoxide; EBLV:European bat lyssavirus; GFP: green fluorescent protein; GST:glutathione S-transferase; hpi: hours post-infection; hpt: hourspost-transfection; LIR: LC3-interactingregion;MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; mCherry:red fluorescent protein; MOI: multiplicity of infection; NC: negativecontrol; MVB: multivesicular body; NEDD4: neural precursorcell-expressed developmentally down-regulated 4; RABV: rabies virus;SQSTM1/p62: sequestosome 1; VLP: virus-like particle; VPS4B: vacuolarprotein sorting 4B; TEM: transmission electron microscopy; WB:western blotting; WT: wild-type; μm: micrometer; μM: micromole.

Bafilomycin 1A Affects p62/SQSTM1 Autophagy Marker Protein Level and Autophagosome Puncta Formation Oppositely under Various Inflammatory Conditions in Cultured Rat Microglial Cells

Regulation of autophagy through the 62 kDa ubiquitin-binding protein/autophagosome cargo protein sequestosome 1 (p62/SQSTM1), whose level is generally inversely proportional to autophagy, is crucial in microglial functions. Since autophagy is involved in inflammatory mechanisms, we investigated the actions of pro-inflammatory lipopolysaccharide (LPS) and anti-inflammatory rosuvastatin (RST) in secondary microglial cultures with or without bafilomycin A1 (BAF) pretreatment, an antibiotic that potently inhibits autophagosome fusion with lysosomes. The levels of the microglia marker protein Iba1 and the autophagosome marker protein p62/SQSTM1 were quantified by Western blots, while the number of p62/SQSTM1 immunoreactive puncta was quantitatively analyzed using fluorescent immunocytochemistry. BAF pretreatment hampered microglial survival and decreased Iba1 protein level under all culturing conditions. Cytoplasmic p62/SQSTM1 level was increased in cultures treated with LPS+RST but reversed markedly when BAF+LPS+RST were applied together. Furthermore, the number of p62/SQSTM1 immunoreactive autophagosome puncta was significantly reduced when RST was used but increased significantly in BAF+RST-treated cultures, indicating a modulation of autophagic flux through reduction in p62/SQSTM1 degradation. These findings collectively indicate that the cytoplasmic level of p62/SQSTM1 protein and autophagocytotic flux are differentially regulated, regardless of pro- or anti-inflammatory state, and provide context for understanding the role of autophagy in microglial function in various inflammatory settings.

Alpha-Asarone attenuates alcohol-induced hepatotoxicity in a murine model by ameliorating oxidative stress, inflammation, and modulating apoptotic-Autophagic cell death

Alcoholic liver disease (ALD) is a major cause of chronic liver injury characterized by steatosis, inflammation, and fibrosis. This study explored the hepatoprotective mechanisms of alpha-asarone in a mouse model of chronic-binge alcohol feeding. Adult male mice were randomized into control, alcohol, and alcohol plus alpha-asarone groups. Serum aminotransferases and histopathology assessed liver injury. Oxidative stress was evaluated via malondialdehyde content, glutathione, superoxide dismutase, and catalase activities. Pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 were quantified by ELISA. P53-mediated apoptosis was determined by immunohistochemistry. Key autophagy markers phospho-AMPK, AMPK, Beclin-1, LC3-I/LC3-II ratio, and LC3 were examined by immunoblotting. Alcohol administration increased serum ALT, AST and ALP, indicating hepatocellular damage. This liver dysfunction was associated with increased oxidative stress, inflammation, p53 expression and altered autophagy. Alpha-asarone treatment significantly decreased ALT, AST and ALP levels and improved histological architecture versus alcohol alone. Alpha-asarone also mitigated oxidative stress, reduced TNF-α, IL-1β and IL-6 levels, ameliorated p53 overexpression and favorably modulated autophagy markers. Our findings demonstrate that alpha-asarone confers protective effects against ALD by enhancing antioxidant defenses, suppressing hepatic inflammation, regulating apoptotic signaling, and restoring autophagic flux. This preclinical study provides compelling evidence for the therapeutic potential of alpha-asarone in attenuating alcohol-induced liver injury and warrants further evaluation as a pharmacotherapy for ALD.

Genome-wide identification and analysis of monocot-specific chimeric jacalins (MCJ) genes in Maize (Zea mays L.)

BACKGROUND

The monocot chimeric jacalins (MCJ) proteins, which contain a jacalin-related lectin (JRL) domain and a dirigent domain (DIR), are specific to Poaceae. MCJ gene family is reported to play an important role in growth, development and stress response. However, their roles in maize have not been thoroughly investigated.

RESULTS

In this study, eight MCJ genes in the maize genome (designated as ZmMCJs) were identified, which displayed unequal distribution across four chromosomes. Phylogenetic relationships between the ZmMCJs were evident through the identification of highly conserved motifs and gene structures. Analysis of transcriptome data revealed distinct expression patterns among the ZmMCJ genes, leading to their classification into four different modules, which were subsequently validated using RT-qPCR. Protein structures of the same module are found to be relatively similar. Subcellular localization experiments indicated that the ZmMCJs are mainly located on the cell membrane. Additionally, hemagglutination and inhibition experiments show that only part of the ZmMCJs protein has lectin activity, which is mediated by the JRL structure, and belongs to the mannose-binding type. The cis-acting elements in the promoter region of ZmMCJ genes predicted their involvement response to phytohormones, such as abscisic acid and jasmonic acid. This suggests that ZmMCJ genes may play a significant role in both biotic and abiotic stress responses.

CONCLUSIONS

Overall, this study adds new insights into our understanding of the gene-protein architecture, evolutionary characteristics, expression profiles, and potential functions of MCJ genes in maize.

Carbon monoxide-induced autophagy enhances human mesenchymal stromal cell function via paracrine actions in murine polymicrobial sepsis

Sepsis is a life-threatening process due to organ dysfunction resulting from severe infections. Mesenchymal stromal cells (MSCs) are being investigated as therapy for sepsis, along with conditioning regimens to improve their function. Carbon monoxide (CO) gas, which is cytoprotective at low doses, induces autophagy and is a mediator of inflammation. We evaluated CO-induced autophagy in human MSCs (hMSCs), and its impact on cell function in murine cecal ligation and puncture. Conditioning of hMSCs with CO ex vivo resulted in enhanced survival and bacterial clearance in vivo, and neutrophil phagocytosis of bacteria in vitro. Decreased neutrophil infiltration and less parenchymal cell death in organs were associated with increased macrophage efferocytosis of apoptotic neutrophils, promoting resolution of inflammation. These CO effects were lost when the cells were exposed to autophagy inhibition prior to gas exposure. When assessing paracrine actions of CO-induced autophagy, extracellular vesicles (EVs) were predominantly responsible. CO had no effect on EV production, but altered their miRNA cargo. Increased expression of miR-145-3p and miR-193a-3p by CO was blunted with disruption of autophagy, and inhibitors of these miRNAs led to a loss of neutrophil phagocytosis and macrophage efferocytosis. Collectively, CO-induced autophagy enhanced hMSC function during sepsis via paracrine actions of MSC-derived EVs.

Alcohol-induced Golgiphagy is triggered by the downregulation of Golgi GTPase RAB3D

The development of alcohol-associated liver disease (ALD) is associated with disorganized Golgi apparatus and accelerated phagophore formation. While Golgi membranes may contribute to phagophores, association between Golgi alterations and macroautophagy/autophagy remains unclear. GOLGA4/p230 (golgin A4), a dimeric Golgi matrix protein, participates in phagophore formation, but the underlying mechanism is elusive. Our prior research identified ethanol (EtOH)-induced Golgi scattering, disrupting intra-Golgi trafficking and depleting RAB3D GTPase from the trans-Golgi. Employing various techniques, we analyzed diverse cellular and animal models representing chronic and chronic/binge alcohol consumption. In trans-Golgi of non-treated hepatocytes, we found a triple complex formed between RAB3D, GOLGA4, and MYH10/NMIIB (myosin, heavy polypeptide 10, non-muscle). However, EtOH-induced RAB3D downregulation led to MYH10 segregation from the Golgi, accompanied by Golgi fragmentation and tethering of the MYH10 isoform, MYH9/NMIIA, to dispersed Golgi membranes. EtOH-activated autophagic flux is evident through increased WIPI2 recruitment to the Golgi, phagophore formation, enhanced LC3B lipidation, and reduced SQSTM1/p62. Although GOLGA4 dimerization and intra-Golgi localization are unaffected, loss of RAB3D leads to an extension of the cytoplasmic N terminal domain of GOLGA4, forming GOLGA4-positive phagophores. Autophagy inhibition by hydroxychloroquine (HCQ) prevents alcohol-mediated Golgi disorganization, restores distribution of ASGR (asialoglycoprotein receptor), and mitigates COL (collagen) deposition and steatosis. In contrast to short-term exposure to HCQ, extended co-treatment with both EtOH and HCQ results in the depletion of LC3B protein via proteasomal degradation. Thus, (a) RAB3D deficiency and GOLGA4 conformational changes are pivotal in MYH9-driven, EtOH-mediated Golgiphagy, and (b) HCQ treatment holds promise as a therapeutic approach for alcohol-induced liver injury.Abbreviation: ACTB: actin, beta; ALD: alcohol-associated liver disease; ASGR: asialoglycoprotein receptor; AV: autophagic vacuoles; EM: electron microscopy; ER: endoplasmic reticulum; EtOH: ethanol; HCQ: hydroxychloroquine; IP: immunoprecipitation; KD: knockdown; KO: knockout; MYH10/NMIIB: myosin, heavy polypeptide 10, non-muscle; MYH9/NMIIA: myosin, heavy polypeptide 9, non-muscle; PLA: proximity ligation assay; ORO: Oil Red O staining; PM: plasma membrane; TGN: trans-Golgi network; SIM: structured illumination super-resolution microscopy.

Unlocking a New Path: An Autophagometer that Measures Flux Using a Non-Fluorescent Immunohistochemistry Method

Macroautophagy/autophagy, a crucial cellular process, is typically measured using fluorescence-based techniques, which can be costly, complex, and impractical for clinical settings. In this paper, we introduce a novel, cost-effective, non-fluorescent immunohistochemistry (IHC) method for evaluating autophagy flux. This technique, based on antigen-antibody reactions and chromogenic detection, provides clear, quantifiable results under standard light microscopy, eliminating the need for expensive equipment and specialized reagents. Our method simplifies technical requirements, making it accessible to routine clinical laboratories and research settings with limited resources. By comparing our approach with traditional fluorescence methods, we demonstrate its superior effectiveness, cost-efficiency, and applicability to patient samples. This innovative technique has the potential to significantly advance autophagy research and improve clinical diagnostics, offering a practical and robust tool for studying autophagy mechanisms in diseases such as cancer and neurodegenerative disorders. Our non-fluorescent IHC method represents a significant step forward in evaluating autophagy flux, making it more accessible and reliable, with the promise of enhancing our understanding and treatment of autophagy-related diseases.

Towards Healthy Longevity: Comprehensive Insights from Molecular Targets and Biomarkers to Biological Clocks

Aging is a complex and time-dependent decline in physiological function that affects most organisms, leading to increased risk of age-related diseases. Investigating the molecular underpinnings of aging is crucial to identify geroprotectors, precisely quantify biological age, and propose healthy longevity approaches. This review explores pathways that are currently being investigated as intervention targets and aging biomarkers spanning molecular, cellular, and systemic dimensions. Interventions that target these hallmarks may ameliorate the aging process, with some progressing to clinical trials. Biomarkers of these hallmarks are used to estimate biological aging and risk of aging-associated disease. Utilizing aging biomarkers, biological aging clocks can be constructed that predict a state of abnormal aging, age-related diseases, and increased mortality. Biological age estimation can therefore provide the basis for a fine-grained risk stratification by predicting all-cause mortality well ahead of the onset of specific diseases, thus offering a window for intervention. Yet, despite technological advancements, challenges persist due to individual variability and the dynamic nature of these biomarkers. Addressing this requires longitudinal studies for robust biomarker identification. Overall, utilizing the hallmarks of aging to discover new drug targets and develop new biomarkers opens new frontiers in medicine. Prospects involve multi-omics integration, machine learning, and personalized approaches for targeted interventions, promising a healthier aging population.